A direct broadcast satellite system has been proposed which will transmit compressed television and other ancillary signals in compressed and packeted form. The system has a potential of transmitting hundreds of programs. Each program may include a number of services. A service is defined herein as a program component, such as a video signal, or an audio signal, or a closed caption signal, or data, etc. The data may include executable computer files or programs for use by appropriate receivers. Each service of each program is identified by a unique service identifier (SCID). Thus if a program includes four service components, the program will be assigned four SCIDs. The information for respective services will be transmitted in packets of predetermined amounts of data (for example 130 bytes) and each packet of information will include a SCID identifier corresponding to the service.
A plurality of programs, for example six to eight, may be transmitted in time division multiplexed form (on a packet basis) on a single carrier frequency. To provide, e.g. 160 programs, the system will transmit on 20 to 28 carriers.
In order to receive a particular program, a receiver must be tuned to a particular carrier, and programmed to select or demultiplex signal packets associated with the desired program. Information associating the service components (SCIDs) with a particular program are contained in a program guide, which is itself a program that is transmitted. Because of the large number of programs and the consequential larger number of services, the programming information associating programs with services is ever changing, and must be continually updated.
The program guide includes information used by respective receivers to associate transmitted time division multiplexed service packets with programs desired to be viewed. The program guide is a program which is assigned a particular SCID that a receiver will automatically select on start up to load the program guide data in memory. The receiver will include a microprocessor, which is responsive to programming commands, to scan the stored program guide and determine the carrier on which a desired program is transmitted and the SCIDs associated with the desired program's service components. Thereafter the receiver tuner will be tuned to the appropriate carrier frequency and packet selection apparatus will route the selected service component packets to corresponding signal processing apparatus.
The program guide information that has been discussed thus far is only machine usable, that is, the SCID information is useful to a receiver apparatus but not of interest to the user. Information of interest to the respective user is the schedule of programs, the times of broadcast, the cost of pay per view programs, what movies or sporting events will be shown, etc. All of this data may also be included in the program guide and arranged in a form conducive to display and perusal. The display and perusal may be performed by conventional menu programming using the receiver On Screen Display apparatus.
Program guide information is segmented into a master guide which is transmitted on substantially all carriers and special guides which are transmitted on only one carrier. The master guide includes limited program information related to the next several viewing hours. The special guides may include comprehensive programming information for an extended period such as a month.
Various program providers may rent space on the broadcast system. Access to program material provided by the various providers may be by subscription. For user convenience, and also to conserve system bandwidth, it is desirable to include programming information for all providers in one program guide. On the other hand, it may be bothersome, for users not subscribing to particular program providers or to particular services available from respective providers, to have to wade through program guide information for which the user has not subscribed. Therefore, a subscriber specific mechanism for precluding display of particular program guide information is desirable.